If you are updating this mod, only extract the assets folder!! Otherwise your achievement progression will be reset.
If you never had this mod, extract everything.

Adds 18 achievements related to the SCAR-20 custom weapon : https://modworkshop.net/mydownloads.php?action=view_down&did=19538
You need the API as well: https://modworkshop.net/mydownloads.php?action=view_down&did=19503

All rewards gives Continental Coins, since it's the most wanted thing.

Extract the content of the archive in PAYDAY 2's root.